ILLUMINATION DEVICE

• US 20110205733A1
• Filed: 11/03/2009
• Published: 08/25/2011
• Est. Priority Date: 11/06/2008
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Lenderink, Egbert, Burgt, Petrus J.M., Van As, Marco
• Granted Patent: US 8,414,138 B2
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 13/08 the elements being filters or photoluminescent elements and reflectors
• CPC Class Codes: F21V 23/0442 activated by means of a sensor, e.g. motion or photodetectors
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21W 2131/405 for shop-windows or displays
• CPC Class Codes: F21Y 2105/00 Planar light sources
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G03B 21/204 using secondary light emission, e.g. luminescence or fluorescence using different colours G03B33/00; if related to video signals H04N9/3197

Abstract

The invention relates to an illumination device (1), comprising: at least one LED (3) having an emission maximum in a first wavelength range; at least one LED (2) having an emission maximum in a second wavelength range; and a wavelength converting material (5) arranged to receive light of at least said first light wavelength range and having an emission maximum in a third wavelength range which is between said first wavelength range and said second wavelength range. The illumination device according to the invention may provide white light of acceptable overall color rendering while producing particularly high saturation of selected colors.

Claims

1. Illumination device, comprising:

at least one LED adapted to emit light having an emission maximum in a first wavelength range;

at least one LED adapted to emit light having an emission maximum in a second wavelength range; and

a wavelength converting material arranged to receive light of at least said first wavelength range and having an emission maximum in a third wavelength range which is between said first wavelength range and said second wavelength range.

2. Illumination device according to claim 1, wherein said first wavelength range is from 400 to 480 nm.

3. Illumination device according to claim 1, wherein said second wavelength range is from 600 to 680 nm.

4. Illumination device according to claim 1, wherein said third wavelength range is from 480 to 600 nm.

5. Illumination device according to claim 1, comprising at least one LED adapted to emit light having an emission maximum in a first subrange of said second wavelength range, and at least one LED adapted to emit light having an emission maximum in a second subrange of said second wavelength range.

6. Illumination device according to claim 5, wherein said first subrange is from 615 to 635 nm and said second subrange is from 635 to 670 nm.

7. Illumination device according to claim 14 wherein said second wavelength range is from 625 to 650 nm.

8. Illumination device according to claim 1, wherein said wavelength converting material (5) comprises the elements Lu, Al, O and Ce and/or Y.

9. Illumination device according to claim 1, wherein said at least one LED having an emission maximum in a first wavelength range and said wavelength converting material are arranged mutually spaced apart.

10. Illumination device according to claim 9, wherein said wavelength converting material is arranged in a light exit window of the illumination device.

11. Illumination device according to claim 1, wherein the wavelength converting material is arranged on said at least one LED having an emission maximum in a first wavelength range.

12. Illumination device according to claim 11, wherein said wavelength converting material is comprised in a plate arranged on said at least one LED having an emission maximum in a first wavelength range.

13. Illumination device according to claim 1, further comprising a control system comprising at least one color sensor adapted to provide first control data representing the color of the mixed color light produced by the LEDs and a control unit for deriving the temperature of each LED, compensating set point values in accordance with second control data including said temperatures and controlling the LEDs in accordance with the differences between the set point values and the first control data.

14. Illumination device according to claim 1, wherein

said first wavelength range is from 420 nm to 460 nm,

said second wavelength range is from 620 nm to 665 nm, and

said third wavelength range is from 500 to 560 nm.